The use of pADPRT inhibitory compounds have been reported for treating cancer and viral infections. Examples of these methods are described in U.S. Pat. Nos. 5,464,871; 5,473,074; 5,482,975; 5,484,951; 5,516,941; and 5,583,155, the disclosures of which are incorporated herein by reference.
In the published literature, 5-iodo-6-amino-1,2-benzopyrone (INH.sub.2 BP), a novel inhibitor of the nuclear enzyme poly-ADP ribose polymerase (pADPRT) has recently been shown to inhibit in vivo tumorigencity in a Ha-ras transfected endothelial cell line; Bauer et al., 1995, "Modification of growth related enzymatic pathways and apparent loss of tumorigenicity of a ras-transformed bovine endothelial cell line by treatment with 5-iodo-6-amino-1,2-benzopyrone (INH.sub.2 BP)," Int. J. Oncol. 8:239-252; Bauer et al., 1995, "Reversal of malignant phenotype by 5-iodo-6-amino-1,2-benzopyrone, a non-covalently binding ligand of poly (ADP-ribose) polymerase," Biochimie 77:347-377. Treatment with INH.sub.2 BP has also resulted in changes in topoisomerase I and II and MAP kinase activity; Bauer et al., 1995, "Modification of growth related enzymatic pathways and apparent loss of tumorigenicity of a ras-transformed bovine endothelial cell line by treatment with 5-iodo-6-amino-1,2-benzopyrone (INH.sub.2 BP)," Int. J. Oncol. 8:239-252; Bauer et al., 1995, "Reversal of malignant phenotype by 5-iodo-6-amino-1,2-benzopyrone, a non-covalently binding ligand of poly (ADP-ribose) polymerase," Biochimie 77:347-377. Based on the effects observed, a hypothesis regarding the potential use of INH.sub.2 BP in the therapy of cancer has been put forward; Bauer et al., 1995, "Modification of growth related enzymatic pathways and apparent loss of tumorigenicity of a ras-transformed bovine endothelial cell line by treatment with 5-iodo-6-amino-1,2-benzopyrone (INH.sub.2 BP)," Int. J. Oncol. 8:239-252; Bauer et al., 1995, "Reversal of malignant phenotype by 5-iodo-6-amino-1,2-benzopyrone, a non-covalently binding ligand of poly (ADP-ribose) polymerase," Biochimie 77:347-377.
Malignant growth and inflammatory processes share the activation of certain cellular signal transduction pathways, e.g., MAP kinase; Kyriakis et al., 1996, "Sounding the alarm: protein kinase cascades activated by stress and inflammation," J. Biol Chem. 271:24313-24316; Ferrell, J E, 1996, "Tripping the switch fantastic: how a protein kinase cascade can convert graded inputs into switch-like outputs," TIBS 21:460-466. Chronic inflammation frequently leads to carcinogenic transformation, as demonstrated, for example, in the case of the intestinal epithelium; Kawai et al., 1993, "Enhancement of rat urinary bladder tumorigenesis by lipopolysaccharide-induced inflammation," Cancer Res. 53:5172-5; Rosin et al., 1994, "Inflammation, chromosomal instability, and cancer: the schistosomiasis model," Cancer Res. 54 (7 Suppl):1929s-1933s; Choi et al., 1994, "Similarity of colorectal cancer in Crohn's disease and ulcerative colitis: implications for carcinogenesis and prevention," Gut 35:950-4. Based on the connection between chronic inflammation and carcinogenic transformation, the aim of the present study was to investigate whether INH.sub.2 BP affects the course of the inflammatory process in vitro and in vivo. In our study, the production of multiple proinflammatory mediators was induced by bacterial lipopolysaccharide (endotoxin, LPS). LPS is known to induce a multitude of cellular reactions and triggers a systemic inflammatory response. LPS-induced pro-inflammatory mediators include tumor necrosis factor alpha (TNF), interleukin-1, interferon-gamma, whereas antiinflammatory mediators include interleukin-10 (IL-10) and interleukin-13; Deltenre et al., 1995, "Gastric carcinoma: the Helicobacter pylori trail," Acta Gastroenterol Belg. 58:193-200; Beutler, 1995, "TNF, immunity and inflammatory disease: lessons of the past decade," J. Invest. Med. 42:227-35; Liles et al., 1995, "Review: nomenclature and biologic significance of cytokines involved in inflammation and the host immune response," J. Infect Dis. 172:1573-80; Giroir, 1993, "Mediators of septic shock: new approaches for interrupting the endogenous inflammatory cascade," Critical Car. Med. 21:780-9. As a consequence of the production of these inflammatory cytokines, LPS initiates the production of inflammatory free radicals (oxygen-centered, such as superoxide, and nitrogen-centered radicals, such as nitric oxide NO!) and of prostaglandins; Nathan, 1992, "Nitric oxide as a secretory product of mammalian cells," FASEB J. 6:3051-3064; Vane, J. R., The Croonian Lecture 1993, "The endothelium: maestro of the blood circulation," Proc. Roy. Soc. Lond B 343:225-246; Szabo, C.; 1995, "Alterations in the production of nitric oxide in various forms of circulatory shock," New Horizons 3:3-32. The production of NO in inflammation is due to the expression of a distinct isoform of NO synthase (iNOS), while the production of inflammatory cytokines is explained by the expression of a distinct isoform of cyclooxygenase (cyclooxygenase-2, COX-2); Nathan, 1992, "Nitric oxide as a secretory product of mammalian cells," FASEB J. 6:3051-3064; Vane, J. R., The Croonian Lecture 1993, "The endothelium: maestro of the blood circulation," Proc. Roy. Soc. Lond B 343:225-246; Szabo, C.; 1995, "Alterations in the production of nitric oxide in various forms of circulatory shock," New Horizons 3:3-32. iNOS, COX-2, as well as the above mentioned pro-inflammatory cytokines and free radicals which play an important role in the LPS-induced inflammatory response; ; Nathan, 1992, "Nitric oxide as a secretory product of mammalian cells," FASEB J. 6:3051-3064; Vane, J. R., The Croonian Lecture 1993, "The endothelium: maestro of the blood circulation," Proc. Roy. Soc. Lond B 343:225-246; Szabo, C.; 1995, "Alterations in the production of nitric oxide in various forms of circulatory shock," New Horizons 3:3-32. Moreover, NO (or its toxic byproduct, peroxynitrite), has been implicated as a key mediator leading to the transformation of the inflammatory response into a carcinogenic process; Bartsch et al., 1994, "Endogenously formed N-nitroso compounds and nitrosating agents in human cancer etiology," Pharmacogenetics 2:272-7; Liu et al., 1992, "Woodchuck hepatitis virus surface antigen induces NO synthesis in hepatocytes: possible role in hepatocarcinogenesis.," Carcinogenesis 15:2875-7; Ohshima et al., 1994, "Chronic infections and inflammatory processes as cancer risk factors: possible role of nitric oxide in carcinogenesis," Mutation Res. 305:253-64. In the current studies, we have first investigated whether treatment with INH.sub.2 BP affects the production of the inflammatory mediators tumor necrosis factor alpha TNF!, interleukin-10, interleukin-6, NO, and prostaglandin in vivo, in LPS-induced models of inflammation.
There are a multitude of intracellular processes which precede the production of proinflammatory mediators. Activation of tyrosine kinases; Levitzki, A., 1994, "Signal-transduction therapy. A novel approach to disease management," Eur. J. Biochem. 226:1-13; Novogrodsky et al., 1994, "Prevention of lipopolysaccharide-induced lethal toxicity by tyrosine kinase inhibitors," Science 264 (Wash):1319-22; Marczin et al., 1993, "Tyrosine kinase inhibitors suppress endotoxin- and IL-1beta-induced NO synthesis in aortic smooth muscle cells," Am. J. Physiol. 265:H1014-1018; mitogen-activated protein kinase (MAP kinase); Matsuda et al., 1994, "Signaling pathways mediated by the mitogen-activated protein (MAP) kinase kinase/MAP kinase cascade," J. Leukocyte Biol. 56:548-53; L'Allemain, G., 1994, "Deciphering the MAP kinase pathway," Progr. Growth Factor Res. 5:291-334; Cowley et al., 1994, "Activation of MAP kinase kinase is necessary and sufficient for PC12 differentiation and for transformation of NIH 3T3 cells.," Cells 77:841-52; and the nuclear factor kappa B (NF-kB) pathway; Baeuerle et al., 1994, "Function and activation of NF- B in the immune system," Ann. Rev. Immunol. 12:141-79; Schreck et al., 1992, "Nuclear factor kappa B: an oxidative stress-responsive transcription factor of eukaryotic cells (a review)," Free Radical Res. Comm. 17:221-37; Muller et al., 1993, "Nuclear factor kappa B, a mediator of lipopolysaccharide effects," Immunobiol. 187:233-56; are recognized as important factors in the inflammatory response and contribute to the expression or production of inflammatory mediators. Therefore, we have also investigated whether INH.sub.2 BP also affects the LPS-induced activation of MAP kinase and the NF-kB by LPS. The results of the current study demonstrate that INH.sub.2 BP has potent antiinflammatory effects by modulating multiple components of the LPS-induced inflammatory response.